Andi Sidwell wrote:
> Maybe feedback time for Media Queries is over, but here goes.
>
> The device-* media features in CSS3 Media Queries are actively harmful
> for authors and leak information that has no need to be exposed via CSS.
>
> In a situation I recently encountered, a page developer had written
> special rules for mobile devices. However, they had written one of them
> testing against max-device-width rather than just max-width. The
> outcome of this was that the page looked fine in a desktop browser when
> squashing the viewport down to 240px, but had display issues when viewed
> on a mobile device of that width. This issue took quite a while to
> track down after it was first submitted as a bug on the mobile's browser
> itself by the developer.
>
> I don't think this will be an atypical case if and when media features
> are more widely used. Copy-and-paste will be used and authors won't
> test adequately, ultimately resulting in quirks for mobile users that
> developers on the lower end of the authoring ladder won't find obvious.
> (The end result could well be that mobile browsers start reporting
> device-width and width as being the same to work round bad authoring
> practice.)
>
> Henri Sivonen has also raised the point that pages can use the
> difference between device-width and max-device width to display annoying
> messages to users saying "maximise this window please". Pages really
> have no business knowing the size of the user's display.
>
>
> As a result, it would be good if the spec was changed to either remove
> device-*, or define when as equivalent to their non-device-*
> counterparts for backwards-compat.
I'm not convinced we should do that, but perhaps the spec can include a note
explaining that in most cases, authors should be avoiding the device-*
features unless they really need to query the device for something. Tutorials
on Media Queries should either leave out the device-* queries (and let people
who really need them look them up elsewhere), or mention them along with a
warning that they should not be used in the general case.
~fantasai